fs/xfs/libxfs/xfs_btree.h

   1 /*
   2  * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #ifndef __XFS_BTREE_H__
  19 #define __XFS_BTREE_H__
  20
  21 struct xfs_buf;
  22 struct xfs_bmap_free;
  23 struct xfs_inode;
  24 struct xfs_mount;
  25 struct xfs_trans;
  26
  27 extern kmem_zone_t      *xfs_btree_cur_zone;
  28
  29 /*
  30  * Generic key, ptr and record wrapper structures.
  31  *
  32  * These are disk format structures, and are converted where necessary
  33  * by the btree specific code that needs to interpret them.
  34  */
  35 union xfs_btree_ptr {
  36         __be32                  s;      /* short form ptr */
  37         __be64                  l;      /* long form ptr */
  38 };
  39
  40 union xfs_btree_key {
  41         xfs_bmbt_key_t          bmbt;
  42         xfs_bmdr_key_t          bmbr;   /* bmbt root block */
  43         xfs_alloc_key_t         alloc;
  44         xfs_inobt_key_t         inobt;
  45 };
  46
  47 union xfs_btree_rec {
  48         xfs_bmbt_rec_t          bmbt;
  49         xfs_bmdr_rec_t          bmbr;   /* bmbt root block */
  50         xfs_alloc_rec_t         alloc;
  51         xfs_inobt_rec_t         inobt;
  52 };
  53
  54 /*
  55  * This nonsense is to make -wlint happy.
  56  */
  57 #define XFS_LOOKUP_EQ   ((xfs_lookup_t)XFS_LOOKUP_EQi)
  58 #define XFS_LOOKUP_LE   ((xfs_lookup_t)XFS_LOOKUP_LEi)
  59 #define XFS_LOOKUP_GE   ((xfs_lookup_t)XFS_LOOKUP_GEi)
  60
  61 #define XFS_BTNUM_BNO   ((xfs_btnum_t)XFS_BTNUM_BNOi)
  62 #define XFS_BTNUM_CNT   ((xfs_btnum_t)XFS_BTNUM_CNTi)
  63 #define XFS_BTNUM_BMAP  ((xfs_btnum_t)XFS_BTNUM_BMAPi)
  64 #define XFS_BTNUM_INO   ((xfs_btnum_t)XFS_BTNUM_INOi)
  65 #define XFS_BTNUM_FINO  ((xfs_btnum_t)XFS_BTNUM_FINOi)
  66
  67 /*
  68  * For logging record fields.
  69  */
  70 #define XFS_BB_MAGIC            (1 << 0)
  71 #define XFS_BB_LEVEL            (1 << 1)
  72 #define XFS_BB_NUMRECS          (1 << 2)
  73 #define XFS_BB_LEFTSIB          (1 << 3)
  74 #define XFS_BB_RIGHTSIB         (1 << 4)
  75 #define XFS_BB_BLKNO            (1 << 5)
  76 #define XFS_BB_LSN              (1 << 6)
  77 #define XFS_BB_UUID             (1 << 7)
  78 #define XFS_BB_OWNER            (1 << 8)
  79 #define XFS_BB_NUM_BITS         5
  80 #define XFS_BB_ALL_BITS         ((1 << XFS_BB_NUM_BITS) - 1)
  81 #define XFS_BB_NUM_BITS_CRC     9
  82 #define XFS_BB_ALL_BITS_CRC     ((1 << XFS_BB_NUM_BITS_CRC) - 1)
  83
  84 /*
  85  * Generic stats interface
  86  */
  87 #define __XFS_BTREE_STATS_INC(mp, type, stat) \
  88         XFS_STATS_INC(mp, xs_ ## type ## _2_ ## stat)
  89 #define XFS_BTREE_STATS_INC(cur, stat)  \
  90 do {    \
  91         struct xfs_mount *__mp = cur->bc_mp; \
  92         switch (cur->bc_btnum) {  \
  93         case XFS_BTNUM_BNO: __XFS_BTREE_STATS_INC(__mp, abtb, stat); break; \
  94         case XFS_BTNUM_CNT: __XFS_BTREE_STATS_INC(__mp, abtc, stat); break; \
  95         case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_INC(__mp, bmbt, stat); break; \
  96         case XFS_BTNUM_INO: __XFS_BTREE_STATS_INC(__mp, ibt, stat); break; \
  97         case XFS_BTNUM_FINO: __XFS_BTREE_STATS_INC(__mp, fibt, stat); break; \
  98         case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break;       \
  99         }       \
 100 } while (0)
 101
 102 #define __XFS_BTREE_STATS_ADD(mp, type, stat, val) \
 103         XFS_STATS_ADD(mp, xs_ ## type ## _2_ ## stat, val)
 104 #define XFS_BTREE_STATS_ADD(cur, stat, val)  \
 105 do {    \
 106         struct xfs_mount *__mp = cur->bc_mp; \
 107         switch (cur->bc_btnum) {  \
 108         case XFS_BTNUM_BNO:     \
 109                 __XFS_BTREE_STATS_ADD(__mp, abtb, stat, val); break; \
 110         case XFS_BTNUM_CNT:     \
 111                 __XFS_BTREE_STATS_ADD(__mp, abtc, stat, val); break; \
 112         case XFS_BTNUM_BMAP:    \
 113                 __XFS_BTREE_STATS_ADD(__mp, bmbt, stat, val); break; \
 114         case XFS_BTNUM_INO:     \
 115                 __XFS_BTREE_STATS_ADD(__mp, ibt, stat, val); break; \
 116         case XFS_BTNUM_FINO:    \
 117                 __XFS_BTREE_STATS_ADD(__mp, fibt, stat, val); break; \
 118         case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break; \
 119         }       \
 120 } while (0)
 121
 122 #define XFS_BTREE_MAXLEVELS     8       /* max of all btrees */
 123
 124 struct xfs_btree_ops {
 125         /* size of the key and record structures */
 126         size_t  key_len;
 127         size_t  rec_len;
 128
 129         /* cursor operations */
 130         struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);
 131         void    (*update_cursor)(struct xfs_btree_cur *src,
 132                                  struct xfs_btree_cur *dst);
 133
 134         /* update btree root pointer */
 135         void    (*set_root)(struct xfs_btree_cur *cur,
 136                             union xfs_btree_ptr *nptr, int level_change);
 137
 138         /* block allocation / freeing */
 139         int     (*alloc_block)(struct xfs_btree_cur *cur,
 140                                union xfs_btree_ptr *start_bno,
 141                                union xfs_btree_ptr *new_bno,
 142                                int *stat);
 143         int     (*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);
 144
 145         /* update last record information */
 146         void    (*update_lastrec)(struct xfs_btree_cur *cur,
 147                                   struct xfs_btree_block *block,
 148                                   union xfs_btree_rec *rec,
 149                                   int ptr, int reason);
 150
 151         /* records in block/level */
 152         int     (*get_minrecs)(struct xfs_btree_cur *cur, int level);
 153         int     (*get_maxrecs)(struct xfs_btree_cur *cur, int level);
 154
 155         /* records on disk.  Matter for the root in inode case. */
 156         int     (*get_dmaxrecs)(struct xfs_btree_cur *cur, int level);
 157
 158         /* init values of btree structures */
 159         void    (*init_key_from_rec)(union xfs_btree_key *key,
 160                                      union xfs_btree_rec *rec);
 161         void    (*init_rec_from_key)(union xfs_btree_key *key,
 162                                      union xfs_btree_rec *rec);
 163         void    (*init_rec_from_cur)(struct xfs_btree_cur *cur,
 164                                      union xfs_btree_rec *rec);
 165         void    (*init_ptr_from_cur)(struct xfs_btree_cur *cur,
 166                                      union xfs_btree_ptr *ptr);
 167
 168         /* difference between key value and cursor value */
 169         __int64_t (*key_diff)(struct xfs_btree_cur *cur,
 170                               union xfs_btree_key *key);
 171
 172         const struct xfs_buf_ops        *buf_ops;
 173
 174 #if defined(DEBUG) || defined(XFS_WARN)
 175         /* check that k1 is lower than k2 */
 176         int     (*keys_inorder)(struct xfs_btree_cur *cur,
 177                                 union xfs_btree_key *k1,
 178                                 union xfs_btree_key *k2);
 179
 180         /* check that r1 is lower than r2 */
 181         int     (*recs_inorder)(struct xfs_btree_cur *cur,
 182                                 union xfs_btree_rec *r1,
 183                                 union xfs_btree_rec *r2);
 184 #endif
 185 };
 186
 187 /*
 188  * Reasons for the update_lastrec method to be called.
 189  */
 190 #define LASTREC_UPDATE  0
 191 #define LASTREC_INSREC  1
 192 #define LASTREC_DELREC  2
 193
 194
 195 /*
 196  * Btree cursor structure.
 197  * This collects all information needed by the btree code in one place.
 198  */
 199 typedef struct xfs_btree_cur
 200 {
 201         struct xfs_trans        *bc_tp; /* transaction we're in, if any */
 202         struct xfs_mount        *bc_mp; /* file system mount struct */
 203         const struct xfs_btree_ops *bc_ops;
 204         uint                    bc_flags; /* btree features - below */
 205         union {
 206                 xfs_alloc_rec_incore_t  a;
 207                 xfs_bmbt_irec_t         b;
 208                 xfs_inobt_rec_incore_t  i;
 209         }               bc_rec;         /* current insert/search record value */
 210         struct xfs_buf  *bc_bufs[XFS_BTREE_MAXLEVELS];  /* buf ptr per level */
 211         int             bc_ptrs[XFS_BTREE_MAXLEVELS];   /* key/record # */
 212         __uint8_t       bc_ra[XFS_BTREE_MAXLEVELS];     /* readahead bits */
 213 #define XFS_BTCUR_LEFTRA        1       /* left sibling has been read-ahead */
 214 #define XFS_BTCUR_RIGHTRA       2       /* right sibling has been read-ahead */
 215         __uint8_t       bc_nlevels;     /* number of levels in the tree */
 216         __uint8_t       bc_blocklog;    /* log2(blocksize) of btree blocks */
 217         xfs_btnum_t     bc_btnum;       /* identifies which btree type */
 218         union {
 219                 struct {                        /* needed for BNO, CNT, INO */
 220                         struct xfs_buf  *agbp;  /* agf/agi buffer pointer */
 221                         xfs_agnumber_t  agno;   /* ag number */
 222                 } a;
 223                 struct {                        /* needed for BMAP */
 224                         struct xfs_inode *ip;   /* pointer to our inode */
 225                         struct xfs_bmap_free *flist;    /* list to free after */
 226                         xfs_fsblock_t   firstblock;     /* 1st blk allocated */
 227                         int             allocated;      /* count of alloced */
 228                         short           forksize;       /* fork's inode space */
 229                         char            whichfork;      /* data or attr fork */
 230                         char            flags;          /* flags */
 231 #define XFS_BTCUR_BPRV_WASDEL   1                       /* was delayed */
 232                 } b;
 233         }               bc_private;     /* per-btree type data */
 234 } xfs_btree_cur_t;
 235
 236 /* cursor flags */
 237 #define XFS_BTREE_LONG_PTRS             (1<<0)  /* pointers are 64bits long */
 238 #define XFS_BTREE_ROOT_IN_INODE         (1<<1)  /* root may be variable size */
 239 #define XFS_BTREE_LASTREC_UPDATE        (1<<2)  /* track last rec externally */
 240 #define XFS_BTREE_CRC_BLOCKS            (1<<3)  /* uses extended btree blocks */
 241
 242
 243 #define XFS_BTREE_NOERROR       0
 244 #define XFS_BTREE_ERROR         1
 245
 246 /*
 247  * Convert from buffer to btree block header.
 248  */
 249 #define XFS_BUF_TO_BLOCK(bp)    ((struct xfs_btree_block *)((bp)->b_addr))
 250
 251
 252 /*
 253  * Check that block header is ok.
 254  */
 255 int
 256 xfs_btree_check_block(
 257         struct xfs_btree_cur    *cur,   /* btree cursor */
 258         struct xfs_btree_block  *block, /* generic btree block pointer */
 259         int                     level,  /* level of the btree block */
 260         struct xfs_buf          *bp);   /* buffer containing block, if any */
 261
 262 /*
 263  * Check that (long) pointer is ok.
 264  */
 265 int                                     /* error (0 or EFSCORRUPTED) */
 266 xfs_btree_check_lptr(
 267         struct xfs_btree_cur    *cur,   /* btree cursor */
 268         xfs_fsblock_t           ptr,    /* btree block disk address */
 269         int                     level); /* btree block level */
 270
 271 /*
 272  * Delete the btree cursor.
 273  */
 274 void
 275 xfs_btree_del_cursor(
 276         xfs_btree_cur_t         *cur,   /* btree cursor */
 277         int                     error); /* del because of error */
 278
 279 /*
 280  * Duplicate the btree cursor.
 281  * Allocate a new one, copy the record, re-get the buffers.
 282  */
 283 int                                     /* error */
 284 xfs_btree_dup_cursor(
 285         xfs_btree_cur_t         *cur,   /* input cursor */
 286         xfs_btree_cur_t         **ncur);/* output cursor */
 287
 288 /*
 289  * Get a buffer for the block, return it with no data read.
 290  * Long-form addressing.
 291  */
 292 struct xfs_buf *                                /* buffer for fsbno */
 293 xfs_btree_get_bufl(
 294         struct xfs_mount        *mp,    /* file system mount point */
 295         struct xfs_trans        *tp,    /* transaction pointer */
 296         xfs_fsblock_t           fsbno,  /* file system block number */
 297         uint                    lock);  /* lock flags for get_buf */
 298
 299 /*
 300  * Get a buffer for the block, return it with no data read.
 301  * Short-form addressing.
 302  */
 303 struct xfs_buf *                                /* buffer for agno/agbno */
 304 xfs_btree_get_bufs(
 305         struct xfs_mount        *mp,    /* file system mount point */
 306         struct xfs_trans        *tp,    /* transaction pointer */
 307         xfs_agnumber_t          agno,   /* allocation group number */
 308         xfs_agblock_t           agbno,  /* allocation group block number */
 309         uint                    lock);  /* lock flags for get_buf */
 310
 311 /*
 312  * Check for the cursor referring to the last block at the given level.
 313  */
 314 int                                     /* 1=is last block, 0=not last block */
 315 xfs_btree_islastblock(
 316         xfs_btree_cur_t         *cur,   /* btree cursor */
 317         int                     level); /* level to check */
 318
 319 /*
 320  * Compute first and last byte offsets for the fields given.
 321  * Interprets the offsets table, which contains struct field offsets.
 322  */
 323 void
 324 xfs_btree_offsets(
 325         __int64_t               fields, /* bitmask of fields */
 326         const short             *offsets,/* table of field offsets */
 327         int                     nbits,  /* number of bits to inspect */
 328         int                     *first, /* output: first byte offset */
 329         int                     *last); /* output: last byte offset */
 330
 331 /*
 332  * Get a buffer for the block, return it read in.
 333  * Long-form addressing.
 334  */
 335 int                                     /* error */
 336 xfs_btree_read_bufl(
 337         struct xfs_mount        *mp,    /* file system mount point */
 338         struct xfs_trans        *tp,    /* transaction pointer */
 339         xfs_fsblock_t           fsbno,  /* file system block number */
 340         uint                    lock,   /* lock flags for read_buf */
 341         struct xfs_buf          **bpp,  /* buffer for fsbno */
 342         int                     refval, /* ref count value for buffer */
 343         const struct xfs_buf_ops *ops);
 344
 345 /*
 346  * Read-ahead the block, don't wait for it, don't return a buffer.
 347  * Long-form addressing.
 348  */
 349 void                                    /* error */
 350 xfs_btree_reada_bufl(
 351         struct xfs_mount        *mp,    /* file system mount point */
 352         xfs_fsblock_t           fsbno,  /* file system block number */
 353         xfs_extlen_t            count,  /* count of filesystem blocks */
 354         const struct xfs_buf_ops *ops);
 355
 356 /*
 357  * Read-ahead the block, don't wait for it, don't return a buffer.
 358  * Short-form addressing.
 359  */
 360 void                                    /* error */
 361 xfs_btree_reada_bufs(
 362         struct xfs_mount        *mp,    /* file system mount point */
 363         xfs_agnumber_t          agno,   /* allocation group number */
 364         xfs_agblock_t           agbno,  /* allocation group block number */
 365         xfs_extlen_t            count,  /* count of filesystem blocks */
 366         const struct xfs_buf_ops *ops);
 367
 368 /*
 369  * Initialise a new btree block header
 370  */
 371 void
 372 xfs_btree_init_block(
 373         struct xfs_mount *mp,
 374         struct xfs_buf  *bp,
 375         __u32           magic,
 376         __u16           level,
 377         __u16           numrecs,
 378         __u64           owner,
 379         unsigned int    flags);
 380
 381 void
 382 xfs_btree_init_block_int(
 383         struct xfs_mount        *mp,
 384         struct xfs_btree_block  *buf,
 385         xfs_daddr_t             blkno,
 386         __u32                   magic,
 387         __u16                   level,
 388         __u16                   numrecs,
 389         __u64                   owner,
 390         unsigned int            flags);
 391
 392 /*
 393  * Common btree core entry points.
 394  */
 395 int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
 396 int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
 397 int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
 398 int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
 399 int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
 400 int xfs_btree_insert(struct xfs_btree_cur *, int *);
 401 int xfs_btree_delete(struct xfs_btree_cur *, int *);
 402 int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
 403 int xfs_btree_change_owner(struct xfs_btree_cur *cur, __uint64_t new_owner,
 404                            struct list_head *buffer_list);
 405
 406 /*
 407  * btree block CRC helpers
 408  */
 409 void xfs_btree_lblock_calc_crc(struct xfs_buf *);
 410 bool xfs_btree_lblock_verify_crc(struct xfs_buf *);
 411 void xfs_btree_sblock_calc_crc(struct xfs_buf *);
 412 bool xfs_btree_sblock_verify_crc(struct xfs_buf *);
 413
 414 /*
 415  * Internal btree helpers also used by xfs_bmap.c.
 416  */
 417 void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
 418 void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);
 419
 420 /*
 421  * Helpers.
 422  */
 423 static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
 424 {
 425         return be16_to_cpu(block->bb_numrecs);
 426 }
 427
 428 static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
 429                 __uint16_t numrecs)
 430 {
 431         block->bb_numrecs = cpu_to_be16(numrecs);
 432 }
 433
 434 static inline int xfs_btree_get_level(struct xfs_btree_block *block)
 435 {
 436         return be16_to_cpu(block->bb_level);
 437 }
 438
 439
 440 /*
 441  * Min and max functions for extlen, agblock, fileoff, and filblks types.
 442  */
 443 #define XFS_EXTLEN_MIN(a,b)     min_t(xfs_extlen_t, (a), (b))
 444 #define XFS_EXTLEN_MAX(a,b)     max_t(xfs_extlen_t, (a), (b))
 445 #define XFS_AGBLOCK_MIN(a,b)    min_t(xfs_agblock_t, (a), (b))
 446 #define XFS_AGBLOCK_MAX(a,b)    max_t(xfs_agblock_t, (a), (b))
 447 #define XFS_FILEOFF_MIN(a,b)    min_t(xfs_fileoff_t, (a), (b))
 448 #define XFS_FILEOFF_MAX(a,b)    max_t(xfs_fileoff_t, (a), (b))
 449 #define XFS_FILBLKS_MIN(a,b)    min_t(xfs_filblks_t, (a), (b))
 450 #define XFS_FILBLKS_MAX(a,b)    max_t(xfs_filblks_t, (a), (b))
 451
 452 #define XFS_FSB_SANITY_CHECK(mp,fsb)    \
 453         (XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
 454                 XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
 455
 456 /*
 457  * Trace hooks.  Currently not implemented as they need to be ported
 458  * over to the generic tracing functionality, which is some effort.
 459  *
 460  * i,j = integer (32 bit)
 461  * b = btree block buffer (xfs_buf_t)
 462  * p = btree ptr
 463  * r = btree record
 464  * k = btree key
 465  */
 466 #define XFS_BTREE_TRACE_ARGBI(c, b, i)
 467 #define XFS_BTREE_TRACE_ARGBII(c, b, i, j)
 468 #define XFS_BTREE_TRACE_ARGI(c, i)
 469 #define XFS_BTREE_TRACE_ARGIPK(c, i, p, s)
 470 #define XFS_BTREE_TRACE_ARGIPR(c, i, p, r)
 471 #define XFS_BTREE_TRACE_ARGIK(c, i, k)
 472 #define XFS_BTREE_TRACE_ARGR(c, r)
 473 #define XFS_BTREE_TRACE_CURSOR(c, t)
 474
 475 bool xfs_btree_sblock_v5hdr_verify(struct xfs_buf *bp);
 476 bool xfs_btree_sblock_verify(struct xfs_buf *bp, unsigned int max_recs);
 477
 478 #endif  /* __XFS_BTREE_H__ */